More than 60 students were absent from a South Boston elementary school on Wednesday as a highly contagious virus, believed to be norovirus, runs through the school.

Approximately 140 students and 10 staff members have become sick with a virus believed to be norovirus over the past few days, said Boston public schools spokesman Lee McGuire. Sixty-one students missed school on Wednesday.

Robby Chisholm, principal of the Condon Elementary School, sent out an automated call to parents Tuesday night informing them about the virus and the school’s efforts to contain it. The elementary school has 800 students and 65 staff members.

Due to the contagiousness of the virus, Chisholm said students who are currently home sick must stay home until they have no symptoms for 24 hours.

Norovirus can be transmitted directly by an infected person, contaminated food or water, or by touching contaminated surfaces, according to the Centers for Disease Control and Prevention. It can cause stomach and intestinal inflammation, stomach pain, nausea, diarrhea, and vomiting.

Chisholm said in the alert that the school has been working closely with the Boston Public Health Commission and the city’s Inspectional Services Division to sanitize the building.

“We have taken steps to sanitize equipment, have added extra soap and more hand sanitizer, and tomorrow we will send flyers home with additional information on what norovirus is and how we are preventing further spread,” Chisholm said in the alert. “Our school nursing department is also sending extra support.”

In an effort to prevent further spread of the virus, teams worked in the school Tuesday night to sanitize the building, Chisholm said.